Base station, apparatus, and radio terminal

Abstract

A base station according to an embodiment is provided in a mobile communication network. The base station includes: a network communication unit configured to receive, from an evolved packet core (EPC), first switching information indicating that a radio terminal switches a communication path with the EPC from the mobile communication network to a wireless LAN; and a controller configured to start measurement of a staying time in which the radio terminal stays in the wireless LAN, in response to reception of the first switching information.

1 . A base station provided in a mobile communication network, comprising:
 a network communication unit configured to receive, from an evolved packet core (EPC), first switching information indicating that a radio terminal switches a communication path with the EPC from the mobile communication network to a wireless LAN; and   a controller configured to start measurement of a staying time in which the radio terminal stays in the wireless LAN, in response to reception of the first switching information.   
     
     
         2 . The base station according to  claim 1 ,
 wherein the first switching information is included in a first message transmitted from the EPC, and   the first message is a message for giving an instruction to release one or more bearers established between the radio terminal and the EPC via the base station.   
     
     
         3 . The base station according to  claim 1 ,
 wherein the network communication unit is configured to receive, from the EPC, second switching information indicating that the radio terminal switches the communication path from the wireless LAN to the mobile communication network, and   the controller is configured to end the measurement of the staying time in response to reception of the second switching information.   
     
     
         4 . The base station according to  claim 3 ,
 wherein the second switching information is included in a second message transmitted from the EPC, and   the second message is a message for requesting establishment of one or more bearers between the radio terminal and the EPC via the base station.   
     
     
         5 . The base station according to  claim 4 ,
 wherein the controller is configured to hold an identifier associated with the radio terminal after the radio terminal switches the communication path to the wireless LAN,   the second message includes an identifier associated with the radio terminal, and   the controller is configured to detect that the radio terminal switches the communication path to the mobile communication network on the basis of the held identifier and the identifier included in the second message.   
     
     
         6 . The base station according to  claim 1 , further comprising,
 a radio communication unit configured to receive, from the radio terminal, second switching information indicating that the radio terminal switches the communication path from the wireless LAN to the mobile communication network, and   the controller is configured to end the measurement of the staying time in response to reception of the second switching information.   
     
     
         7 . The base station according to  claim 6 ,
 wherein the second switching information is included in a third message transmitted from the radio terminal, and   the third message is a message for establishing an RRC connection between the radio terminal and the base station or a message for reconfiguring an RRC connection between the radio terminal and the base station.   
     
     
         8 . The base station according to  claim 7 ,
 wherein the controller is configured to hold an identifier associated with the radio terminal after the radio terminal switches the communication path to the wireless LAN,   the third message includes an identifier associated with the radio terminal, and   the controller is configured to detect that the radio terminal switches the communication path to the mobile communication network on the basis of the held identifier and the identifier included in the third message.   
     
     
         9 . The base station according to  claim 3 ,
 wherein the network communication unit is configured to receive a threshold value from the EPC,   the controller is configured to compare the measured staying time with the threshold value, and to decide parameters when the staying time is less than the threshold value, and   the parameters are parameters used for determining whether or not the radio terminal switches the communication path from the mobile communication network to the wireless LAN.   
     
     
         10 . An apparatus constituting an evolved packet core (EPC), comprising:
 a controller configured to start measurement of a staying time in which a radio terminal stays in a wireless LAN when the controller detects that the radio terminal switches a communication path with the EPC from a mobile communication network to the wireless LAN.   
     
     
         11 . The apparatus according to  claim 10 ,
 wherein when the controller detects that the radio terminal switches the communication path from the wireless LAN to the mobile communication network, the controller is configured to end the measurement of the staying time, and to give a notification of information based on the staying time to a base station constituting the mobile communication network.   
     
     
         12 . A radio terminal configured to
 transmit, to a base station constituting a mobile communication network, switching information indicating that a communication path with an evolved packet core (EPC) is switched from a wireless LAN to the mobile communication network,   wherein the switching information is included in a message for establishing an RRC connection between the radio terminal and the base station or a message for reconfiguring an RRC connection between the radio terminal and the base station.